无法使图像在Qt的中心旋转 [英] can't get the image to rotate in center in Qt
本文介绍了无法使图像在Qt的中心旋转的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试在QLabel Widge内旋转89x89图像.
i am trying to rotate a 89x89 image inside the QLabel Widge.
#include "header.h"
disc::disc(QWidget *Parent) : QWidget(Parent)
{
orig_pixmap = new QPixmap();
rotate = new QLabel(this);
showDegrees = new QLabel(this);
orig_pixmap->load("pic.png");
degrees = 0;
rotate->resize(89,89);
rotate->move(100,10);
rotate->setStyleSheet("QLabel{background-color:red;}");
showDegrees->resize(100,100);
showDegrees->move(400,0);
}
void disc::rotate_disc()
{
QString string;
degrees++;
if(degrees == 360) degrees = 0;
QTransform rotate_disc;
rotate_disc.translate( (orig_pixmap->width()-rotate->width())/2 , (orig_pixmap->width()-rotate->height())/2);
rotate_disc.rotate(degrees,Qt::ZAxis);
QPixmap pixmap;
//pixmap = orig_disc->scaled(89,89,Qt::IgnoreAspectRatio,Qt::SmoothTransformation);
pixmap = orig_pixmap->transformed(rotate_disc,Qt::SmoothTransformation);
rotate->setPixmap(pixmap);
string.append("Degrees: " + QString::number(degrees) + "*");
showDegrees->setText(string);
}
即使它旋转.图像的一半滚动到QLabel之外,因此该侧不可见.我如何使其中心在图像中心的原点(0,0)处旋转.
Even though it rotates. The image's half gets rolled outside the QLabel and hence that side is not visible.How can i make it center rotate at origin(0,0) of the image center.
这是文件
http://www65.zippyshare.com/v/85775455/file.html
如果查看它,您会看到图像就像向左跳动.我如何使其在黑色区域内旋转.
if you look at it you can see that image is like bouncing to the left.how can i make it rotate inside the black area.
我每10ms设置一个Rotate_disc()函数的信号超时.我正在用它来深入学习Qt.
i setup a signal timeout at every 10ms to the rotate_disc() function. I am using this to learn Qt indepth.
谢谢!
推荐答案
我已经这样做了...
I've done it like this...
//Move windows's coordinate system to center.
QTransform transform_centerOfWindow( 1, 0, 0, 1, width()/2, height()/2 );
//Rotate coordinate system.
transform_centerOfWindow.rotate( m_LoadingDisk_degrees );
//Draw image with offset to center of image.
QPainter painter( this );
//Transform coordinate system.
painter.setTransform( transform_centerOfWindow );
//Load image.
//Notice: As coordinate system is set at center of window, we have to center the image also... so the minus offset to come to center of image.
painter.drawPixmap( -loadingDisk.width()/2, -loadingDisk.height()/2, loadingDisk );
这篇关于无法使图像在Qt的中心旋转的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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